Bore Size and Bullet Diameter.

[Marlin Kid]

I have been playing around with several different loads lately for the up coming hunting season. I have probably shot about 50-60 rounds of factory ammo and about 30-40 rounds of reloads. So far I have not been able to get less than 5 inches at 50 yards. All the ammo (factory and reloads) have been .459 dia. My barrel is a Micro Groove and I have read some on how you usually need a bullets slightly bigger than your bore diameter (correct me if I am wrong).
I slugged my barrel twice and it came out to just shy of .459. I was thinking about ordering some of Bear Tooth's Pile Drivers with a .460 diameter to see if it improved the accuracy. I just wanted to see what the opinion was on here before I did anything.

[airwinky]

My .45-70's have the "ballard" style rifling, and are super accurate with .459 bullets.
Near or at MOA, sometimes better, if I do my part.
My experience with micro-groove in other calibers, and with the similar (shallow) rifling found in some of the Browning Winchester repro's, has been that they did better with jacketed bullets or with gaschecked lead, than with straight cast lead bullets.
My brother and I both have .35 Rem 336's with micro-groove, and they will shoot cloverleafs at 50yds and slightly over an inch at a hundred with Buffalo Bore JSP's, and nearly as well with std factory jacketed stuff.
My Browning '92 in .44 mag wouldn't shoot "cowboy" lead loads worth a damn, but going to jacketed and gaschecked bullets improved accuracy.
Going oversize with plain lead bullets made the problem worse.
I would think the .460 Beartooth's, (gaschecked), would help.

[me]

Marlin Kid Please let me ask a few stupid questions

And Yes the micro groove will shoot them .460 OK since you got your barrel slugged...
Have you checked the barrel for leading... or copper
If you got a scope on it... do you know it is secure, and functioning
What cast bullets you shooting and at what speed... these guys will like to know...
Same for Iorn (can't imagine but are they loose)

Right off I think your barrel is fouled

[Marlin Kid]

No I haven't checked the barrel for leading or copper, lol I guess I should have done that first
I had a scope on it but I removed it to see if it was causing the problem and found it was not. The Iron sights are XS ghost rings and they are very secure.
I have been using 460gr FNGC cast performance bullets and some 405gr cast HSM bullets and I have been running them at around 1600-1700 fps.
Your probably right about the barrel being fouled Ill clean it and see it that helps. Thanks for refreshing my memory on that

Marlin Kid Please let me ask a few stupid questions

And Yes the micro groove will shoot them .460 OK since you got your barrel slugged...
Have you checked the barrel for leading... or copper
If you got a scope on it... do you know it is secure, and functioning
What cast bullets you shooting and at what speed... these guys will like to know...
Same for Iorn (can't imagine but are they loose)

Right off I think your barrel is fouled

[Crummy]

some 405gr cast HSM bullets

I read somewhere in the last few days that those may leave some lead behind. I see that Sportsman warehouse here has several boxes in stock but I can't find any information on them from the HSM website or anyplace else. The only thing I found was a post about them leading the barrel. I would not take that as hard fact as it was only mentioned in one post I found but it would be worth checking. Do they have a gas check? It doesn't say it on the box but I didn't rip it open to see.

[me]

Marlin Kid You know what Elbow grease is.... You going to need some to clean that barrel

Yeah I here Micro Grooves can collect lead... and at that speed I'm sure you got plenty. Don't use abrasive cleaners and stay with a brass brush. I think you will find info on the How too section I don't get there to often leave some solvent in your barrel to free that lead up.

I shoot few lead bullets... but let me help ya... Some lead bullets are soft and probably not good for over 1000fps.
A hard cast has been heat treated and will take you up to Maybe 1600fps and a gas check will take you upwards of 2000 (again I'm not sure my hard cast are at 1300 and under and I ain't using a micro barrel.) Not to villianize Micro, it's just different that way

Hope some guys will weigh in (because you ain't the 1st guy to lead a barrel around here)

[me]

less someone gives you good info... look at this thread.

Get the lead out

[ButterNutZ]

Kid you need a bullet that is at least .460, I would see if you can find a .461 sized slugs. My GBL slugs right at .458 and I'm running .460's in her with great results. I'm running 430gr at 1700fps and get 2 inch groups at 100 yards. My bet is that those bullets are way to small hoss.
If the barrel is not to badly leaded just shoot couple of condom bullets through it and all the lead will be gone.

[Marlin Kid]

I bought a box of 250 for just reloading. No they aren't GC. Yeah I did some looking around and couldn't find much on them either. I will probably start loading them down then. Thanks!

I read somewhere in the last few days that those may leave some lead behind. I see that Sportsman warehouse here has several boxes in stock but I can't find any information on them from the HSM website or anyplace else. The only thing I found was a post about them leading the barrel. I would not take that as hard fact as it was only mentioned in one post I found but it would be worth checking. Do they have a gas check? It doesn't say it on the box but I didn't rip it open to see.

[kd115]

my barrel dia. is 459.5